Tayfun Sönmez '95

Tayfun SönmezA leader in the field of matching, Tayfun Sonmez has made numerous contributions to economic theory and practice. In addition to pioneering the study of school assignment, he has developed and applied theory to the Cadet Branch and ROTC program matching as well as the allocation of transplantable organs including kidneys, lungs, and livers.

Perhaps best known for his work on school choice, Tayfun’s 2003 paper with Atila Abdulkadiroglu kick-started the study of procedures to assign students to schools. That seminal paper proposed and compared two incentive-compatible mechanisms which led to substantive changes in procedures employed in Boston and districts throughout the country. In subsequent work, he has tested procedures experimentally and developed new techniques to accommodate affirmative action goals. Beyond school choice, Tayfun’s 2004 paper with Al Roth and Utku Ünver applies similar techniques to study and recommend improvements for kidney exchange. Tayfun has recently set his sights on improving liver and lung exchanges leveraging possibilities opened by medical advances.

Tayfun’s contributions to theory are no less substantive. In an important early paper, he proved a general theorem relating the core and strategy-proof mechanisms which unified and subsumed numerous classical results. Similarly, in work with Atila Abdulkadiroglu, he described properties of efficient randomized allocations and discovered an essential equivalence between randomization over endowment profiles and priority orders. Tayfun and Atila also collaborated to define a new object allocation procedure to account for individuals with initial endowments. Each of these results provides a touchstone for ongoing work.

Beginning with the economics department’s Conibear Prize, Tayfun’s list of honors and awards now includes the Social Choice and Welfare Prize (2008), induction into the Science Academy of Turkey (2014), and fellowship in the Economic Theory (2016) and Econometric Societies (2003). Tayfun is also sought-after as a speaker with invited presentations at meetings of the Econometric Society (2010, 2012), Social Choice and Welfare Society (2008), and Society of Economic Design (2013). He is now an associate editor of Econometrica.

Tayfun has emphasized practical applications throughout his career. His passion has led him into the political arena where he has alternatively worked with and challenged policy makers, spurring reforms in numerous school districts. In addition to policy makers, Tayfun engages with students at all levels. He continues to work with and supervise graduate students, teach mini-courses, and organize conferences. His enthusiasm and charisma continue to inspire young researchers to engage with theory and apply it to practice.

Now at Boston College, Tayfun leads a team of researchers focused on applying theory to achieve social goals. Tayfun first studied electrical engineering as an undergraduate at Bilkent before turning his attention to economics. He worked at Koç University and his initial placement, the University of Michigan, before moving his current position. Tayfun worked with William Thomson at the University of Rochester.


Random Serial Dictatorship and the Core from Random Endowments in House Allocation Problems (with Atila Abdulkadiroglu), Econometrica, 1998.

House allocation with existing tenants (with Atila Abdulkadiroglu), Journal of Economic Theory, 1999.

Strategy‐proofness and Essentially Single‐valued Cores. Econometrica, 1999.

School Choice: A Mechanism Design Approach (with Atila Abdulkadiroglu), American Economics Review, 2003.

Kidney Exchange (with Al Roth and Utku Ünver), Quarterly Journal of Economics, 2004.